(1) Field of the Invention
The present invention relates to a colored resin fine particle water base dispersion liquid for a water base ink which is a base material for ink, and a water base ink composition which does not cause blur in writing and is useful for writing tools such as a sign pen and a ball point pen or an ink jet recording apparatus.
(2) Description of the Prior Art
Dyes and pigments are known as coloring components for water base inks which are used for writing tools such as a water base sign pen and a water base ball point pen.
Inks using dyes have the problems that because of water solubility of the dyes, the written characters and the drawn lines are blurred or disappear due to sweat and water to make the written characters and the drawn lines indistinct. That is, they are inferior in waterproof. Further, dyes themselves are inferior in light fastness and therefore have the problem that the written characters and the drawn lines are deteriorated during a long period of time.
On the other hand, inks using pigments have no problems on waterproof and light fastness, but the pigments coagulate or settle down during a long period of time to cause the problems of clogging at pen points, inferior writing and the like. Further, pigments are required to be finely dispersed in inks for writing tools, and therefore it is difficult to disperse various color pigments to increase the number of colors.
Ink compositions prepared by dissolving water soluble acid dyes basic dyes or the like in water base media and further adding additives such as a humidifier, a pH controller and a preservative are known as conventional ink compositions for an ink jet recording apparatus.
However, these ink compositions have the defects that the printed parts are blurred to make the images indistinct, or because of the water solubility of the dyes, the recorded images are blurred or disappear due to sweat and water and that color mixing makes the colors turbid. Originally, water soluble dyes have the problem that they are inferior in light fastness and therefore storage of the printed matters over a long period of time deteriorates the images. Further, these ink compositions have the defect that storage thereof over a long period of time or repeated printing changes the physical properties of the inks or causes precipitates to clog nozzles or bring about marked troubles on discharge of the inks, which results in causing inferior printing.